THIRUVANANTHAPURAM: Giving enough reasons for the state to worry, a study report tabled in Parliament by the Ministry of Earth Sciences reveals that 41% of the coastline in Kerala is under varying degrees of coastal erosion. The National Centre for Coastal Research has monitored the shoreline changes along 6,632km of Indian coastline from 1990 to 2018. The results of the study are mainly classified into three different categories — erosion, stable and accretion.
The overall long-term (1990-2018) shoreline change result shows that about 32% of the coastline is under varying degrees of erosion, while 27% is of accreting nature and the remaining 41% is in a stable state. The state-wise shoreline analysis reveals that 60% of the West Bengal coast was noticed with varying degrees of erosion followed by Puducherry (56%), Kerala (41%) and Tamil Nadu (41%). Accretion was dominant along the Odisha coast with 51% followed by Andhra Pradesh (48%).
This is not the first time the grave situation along the 590km-long coastline — one of the most densely populated in the country and exposed to rogue waves — is being exposed. The ‘National assessment of shoreline changes along Indian coast: A status report for 26 years (1990-2016)’ prepared by the National Centre for Coastal Research had revealed that around 45% of Kerala’s coastline is eroding while 34% is stable and 21% accreting. The report said coasts of Kasaragod, Kannur, Malappuram, Ernakulam and Kollam are dominated by both erosion and stable condition with a few pockets of accretion.
Another study, ‘Coastal Morphology and Long-term Shoreline Changes along the Southwest Coast of India’, conducted by the National Centre for Earth Science Studies and published in Journal Geological Society of India, revealed that almost 60% of the state’s coastline is eroding with about 29% showing an accreting trend. A 46-year-period from 1968 to 2014 was studied using multi-dated shoreline images and Survey of India topographic charts.
All these studies point to factors like construction of structures such as fishing harbours, ports, groynes, sea walls and beach sand mining for monazite ores for altering the nature of the coastline and induced changes.
M C Dathan, scientific advisor to the chief minister and a former director of ISRO’s Vikram Sarabhai Space Centre (VSSC), said, “Coastal erosion is more vigorous and rampant along the coastline of Kerala as more energy is stored in the waves of the Arabian Sea as compared to the Bay of Bengal. There are a lot of global factors which influence the sea surface temperature and wind patterns over the sea. We have been following various methods like construction of a sea wall, diaphragm wall etc here to dampen the force of waves. It is to some extent useful but, certainly, more needs to be done.”